﻿// -----------------------------------------------------------------------------
// DM 是 .NET 5 平台下开发管理的系统。
// Copyright © 2021 DM,  Co.,Ltd.
//
// 框架名称：Furion
// 后台框架：ABC.Admin
// -----------------------------------------------------------------------------

using Furion.DataEncryption.Extensions;

using Microsoft.AspNetCore.Http;

using System;
using System.Drawing;
using System.Drawing.Imaging;
using System.IO;
using System.Text;

namespace Tool
{
    public partial class WebHelper
    {
        /// <summary>
        /// 获取图片验证码
        /// </summary>
        /// <param name="httpContextAccessor"></param>
        /// <param name="code">生成的验证码原文</param>
        /// <param name="verifyKey">验证码Key（如：Admin）</param>
        /// <param name="codeLenght">验证码长度</param>
        /// <param name="randType">验证码字符类型</param>
        /// <returns></returns>
        public static byte[] GetVerifyCode(IHttpContextAccessor httpContextAccessor, string verifyKey = "Admin", int codeLenght = 4, RandType randType = RandType.Num)
        {
            System.Text.Encoding.RegisterProvider(System.Text.CodePagesEncodingProvider.Instance);
            var code = RandomHelper.GetString(codeLenght, randType);
            var codebyte = GetVerifyCode(code);
            var vercode = code.ToPBKDF2();
            httpContextAccessor.HttpContext.Session.SetString(verifyKey, vercode);
            return codebyte;
        }

        /// <summary>
        /// 验证输入的验证码
        /// </summary>
        /// <param name="httpContextAccessor"></param>
        /// <param name="inputVerifyCode">输入的验证码</param>
        /// <param name="verifyKey">验证码Key（如：Admin）</param>
        /// <returns></returns>
        public static bool VerifyCode(IHttpContextAccessor httpContextAccessor, string inputVerifyCode, string verifyKey = "Admin")
        {
            System.Text.Encoding.RegisterProvider(System.Text.CodePagesEncodingProvider.Instance);
            var state = httpContextAccessor.HttpContext.Session.TryGetValue(verifyKey, out byte[] vbytes);
            if (state == false) return false;//没有找到存储在session的图片验证码
            var encryptText = Encoding.UTF8.GetString(vbytes);
            // var code2 = inputVerifyCode.top;
            if (inputVerifyCode.ToPBKDF2Compare2(encryptText))
            {
                httpContextAccessor.HttpContext.Session.Remove(verifyKey);
                return true;
            }

            //if (scode.Trim().ToLower() == code2.Trim().ToLower())
            //{
            //    httpContextAccessor.HttpContext.Session.Remove(verifyKey);
            //    return true;
            //}

            return false;
        }

        private static byte[] GetVerifyCode(string code)
        {
            const int codeW = 80;
            const int codeH = 30;
            const int fontSize = 16;
            //string chkCode = string.Empty;
            //颜色列表，用于验证码、噪线、噪点
            Color[] color = { Color.Black, Color.Red, Color.Blue, Color.Green, Color.Orange, Color.Brown, Color.Brown, Color.DarkBlue };
            //字体列表，用于验证码
            string[] font = { "Times New Roman" };
            //验证码的字符集，去掉了一些容易混淆的字符
            //char[] character = { '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'd', 'e', 'f', 'h', 'k', 'm', 'n', 'r', 'x', 'y', 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'J', 'K', 'L', 'M', 'N', 'P', 'R', 'S', 'T', 'W', 'X', 'Y' };
            Random rnd = new Random();
            ////生成验证码字符串
            //for (int i = 0; i < 4; i++)
            //{
            //    chkCode += character[rnd.Next(character.Length)];
            //}
            //写入Session、验证码加密
            //WebHelper.WriteSession("czfw_session_verifycode", DesEncrypt.Encrypt(chkCode.ToLower(), "MD5"));

            //创建画布
            Bitmap bmp = new Bitmap(codeW, codeH);
            Graphics g = Graphics.FromImage(bmp);
            g.Clear(Color.White);
            //画噪线
            for (int i = 0; i < 3; i++)
            {
                int x1 = rnd.Next(codeW);
                int y1 = rnd.Next(codeH);
                int x2 = rnd.Next(codeW);
                int y2 = rnd.Next(codeH);
                Color clr = color[rnd.Next(color.Length)];
                g.DrawLine(new Pen(clr), x1, y1, x2, y2);
            }
            //画验证码字符串
            for (int i = 0; i < code.Length; i++)
            {
                string fnt = font[rnd.Next(font.Length)];
                Font ft = new Font(fnt, fontSize);
                Color clr = color[rnd.Next(color.Length)];
                g.DrawString(code[i].ToString(), ft, new SolidBrush(clr), (float)i * 18, 0);
            }
            //将验证码图片写入内存流，并将其以 "image/Png" 格式输出
            MemoryStream ms = new MemoryStream();
            try
            {
                bmp.Save(ms, ImageFormat.Png);
                return ms.ToArray();
            }
            catch (Exception)
            {
                return null;
            }
            finally
            {
                g.Dispose();
                bmp.Dispose();
            }
        }
    }
}
